.header {
  top: 0;
  display: flex;
  align-items: center;
  padding-left: px2rem(20);
  padding-: px2rem(20);
  background: #eee;
  position: fixed;
  width: 100%;
  max-width: 750px;
}

.center {
  display: flex;
  align-items: center;
  justify-content: center;
}